griddims subroutine

Inquire about the coordinates, time, level and variable type of a NetCDF dataset.

How to use

subroutine griddims(ifile, idata)
Parameters:
Return:
  • ndims :: number of dimensions of variable
  • nlons :: number of longitudes
  • nlats :: number of latitudes
  • ntimes :: number of times [3d and 4d datasets]
  • nlevels :: number of levels [4d datasets]
  • lonunits :: longitude units
  • latunits :: latitude units
  • timeunits :: time units [3d and 4d datasets]
  • levelunits :: level units [4d datasets]
  • vartype :: variable type
  • varunits :: variable units
  • long_name :: long name
  • _FillValue :: fill value
Call :

griddims(ifile,idata)
[1](1, 2) Defined by user

[Code example] Read dataset information

Get the number of latitudes and longitudes of a file.

program main
  use fpl
  implicit none

  !  Source: UNIDATA
  !    file: test_echam_spectral.nc
  !download: http://www.unidata.ucar.edu/software/netcdf/examples/files.html                  

  !Set float datatype 3d dataset with, longitude and latitude and time in double datatype  
  type(nc3d_float_lld_td) :: spectral

  !Input and Output declarations
  character(100) :: inputpath, outputpath

  inputpath = "database/test_echam_spectral.nc"
  
  outputpath = "database/spectral.nc"

  !Set necessary parameters for read the data
  spectral%varname = "albedo_nir"
  spectral%timename = "time"
  spectral%lonname = "lon"
  spectral%latname = "lat"

  !Call function to read the data (readgrid(input_data_path, defined_data_structure))
  call readgrid(inputpath, spectral)
  
  write(*,*) "====== Dataset Information ======="
  write(*,*) "=================================="
  
  !Get data information using pointer to structures
  write(*,*) "Grid 4d info ================================="
  write(*,100) "varname :    ",   spectral%varname  
  write(*,100) "timename :   ",   spectral%timename
  write(*,100) "latname :    ",   spectral%latname
  write(*,100) "lonname :    ",   spectral%lonname
  write(*,100) "long_name :  ",   spectral%long_name
  write(*,100) "varunits :   ",   spectral%varunits 
  write(*,100) "timeunits :  ",   spectral%timeunits
  write(*,100) "lonunits :   ",   spectral%lonunits
  write(*,100) "latunits :   ",   spectral%latunits
  write(*,102) "nlons :      ",    spectral%nlons
  write(*,102) "nlats :      ",    spectral%nlats
  write(*,102) "ntimes :     ",    spectral%ntimes
  write(*,102) "ndims :      ",    spectral%ndims
  write(*,102) "vartype :    ",    spectral%vartype
  write(*,'(a13,f10.4)') "FillValue :  ", spectral%FillValue
   
100 format(a13,a25)
101 format(a13,3a20)
102 format(a13,i4)
103 format(a13,3i4)
 
  !Write the data on file
  call writegrid(outputpath, spectral) 
    
end program main

#RedHat based systems
gfortran -o griddims.out griddims.f90 -I/usr/lib64/gfortran/modules/ -lFPL

#Debian based systems
gfortran -o griddims.out griddims.f90 -I/usr/include/ -lFPL

Important

-I<dir> This option specifies where to put .mod files for compiled modules. It is also added to the list of directories to Influencing the linking step. See the GNU Fortran Compiler Documentation .

<dir> is defined in Makefile as $(FPL_moddir). See Build Library.

After compilation run the program ./griddims.out